/***********************************************************************
 * Software License Agreement (BSD License)
 *
 * Copyright 2008-2009  Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
 * Copyright 2008-2009  David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
 *
 * THE BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *************************************************************************/

#ifndef OPENCV_FLANN_LOGGER_H
#define OPENCV_FLANN_LOGGER_H

#include <stdio.h>
#include <stdarg.h>

#include "defines.h"

#pragma warning(disable:4996)

namespace cvflann
{

	class Logger
	{
		Logger() : stream(stdout), logLevel(FLANN_LOG_WARN) {}

		~Logger()
		{
			if ((stream != NULL) && (stream != stdout)) {
				fclose(stream);
			}
		}

		static Logger& instance()
		{
			static Logger logger;
			return logger;
		}

		void _setDestination(const char* name)
		{
			if (name == NULL) {
				stream = stdout;
			}
			else {
				stream = fopen(name, "w");
				if (stream == NULL) {
					stream = stdout;
				}
			}
		}

		int _log(int level, const char* fmt, va_list arglist)
		{
			if (level > logLevel) return -1;
			int ret = vfprintf(stream, fmt, arglist);
			return ret;
		}

	public:
		/**
		 * Sets the logging level. All messages with lower priority will be ignored.
		 * @param level Logging level
		 */
		static void setLevel(int level) { instance().logLevel = level; }

		/**
		 * Sets the logging destination
		 * @param name Filename or NULL for console
		 */
		static void setDestination(const char* name) { instance()._setDestination(name); }

		/**
		 * Print log message
		 * @param level Log level
		 * @param fmt Message format
		 * @return
		 */
		static int log(int level, const char* fmt, ...)
		{
			va_list arglist;
			va_start(arglist, fmt);
			int ret = instance()._log(level, fmt, arglist);
			va_end(arglist);
			return ret;
		}

#define LOG_METHOD(NAME,LEVEL) \
    static int NAME(const char* fmt, ...) \
    { \
        va_list ap; \
        va_start(ap, fmt); \
        int ret = instance()._log(LEVEL, fmt, ap); \
        va_end(ap); \
        return ret; \
    }

		LOG_METHOD(fatal, FLANN_LOG_FATAL)
			LOG_METHOD(error, FLANN_LOG_ERROR)
			LOG_METHOD(warn, FLANN_LOG_WARN)
			LOG_METHOD(info, FLANN_LOG_INFO)

	private:
		FILE* stream;
		int logLevel;
	};

}

#endif //OPENCV_FLANN_LOGGER_H
